Method and device for deflecting a rocket jet



Feb. 8, 1966 J. H. BERTIN ETAL 3,233,833

METHOD AND DEVICE FOR DEFLECTING A ROCKET JET 4 Sheets-Sheet 1 FiledFeb. 4,

MW M'TioRNEYs Feb. 8, 1966 J. H. BERTIN ETAL 3,233,833

METHOD AND DEVICE FOR DEFLECTING A ROCKET JET 4 Sheets-Sheet 2 FiledFeb. 4:, 1963 INV'ENTCIJRS Jed/7 A. Berzm CynzZ/e f flaw/Z72 dz/WiTTORNEYS Feb. 8, 1966 J. H. BERTlN ETAL 3,233,833

METHOD AND DEVICE FOR DEFLECTING A ROCKET JET 4 Sheets-Sheet 5 FiledFeb. 4, 1965 A ORNEYS 1966 J. H. BERTIN ETAL 3,

METHOD AND DEVICE FOR DEFLECTING A ROCKET JET Filed Feb. 4, 1963 4Sheets-$heet 4 INYENTORS dean Her ia ATTORNEYS United States PatentOfifice Patented Feb. 8, 1966 3,233,833 METHOD AND DEVICE FOR DEFLECTINGA-ROCKET JET Jean Henri Bertin, Neuilly-sur-Seine, and Cyrille FrancoisPavlin, Cormeilles-en-Parisis, France, assignors to Societe Bertin &Cie, Paris, France, a company of France Filed Feb. 4, 1963, Ser. No.255,938 Claims priority, application France, Feb. 8, 1962, 887,391; Jan.15, 1963, 921,523 11 Claims. (Cl. 239-26523) It is well known to deflectthe propulsive supersonic jet delivered by a rocket nozzle for steeringpurposes by means of transverse nozzles divided into sectors andsupplied with a gaseous or liquid fluid under pressure. The deflectionsustained by the rocket jet is caused by the momentum of the fluid andthis is therefore a purely mechanical control process.

In order to reduce the amount of control fluid which is necessary toproduce a given deflection, it has been proposed to create local fluidobstacles or expansion zones at the inner periphery of a rocket nozzle.The gas flow within said nozzle is then asymmetrically *blocked" whensupersonic, by a localized shock wave at least, and deviated in everycase. The control fluids proposed consisted either in a pressurized gasor, in the case of jets containing yet an excess of air or oxidizer intheir exhaust state, in fuel capable to burn in said excess therebygenerating supplemental motive power.

A first object of this invention is to bring an improved reduction ofthe control fluid amount.

Another object of the invention is to allow deflection of a jetcontaining no excess of air or oxidizer in its exhaust state.

Another object of the invention is to produce local and temporary fluidobstacles limited to the close vicinity of the nozzle wall.

According to this invention, two reactive liquids are successivelyinjected in the boundary layer hugging the nozzle wall internally, insuch manner as to react with each other within said boundary layer. Therelatively important local expansion caused by the reaction is followedby the creation of a local shock wave, at least, which deflects thepropulsive jet.

With certain reactive liquids or propellants, the time elapsing beforethe chemical reactions which liberate their energy are triggered islonger than the time the propulsive gas jet dwells in the nozzle, It istherefore desirable to keep the propellants inside the nozzle for anadequate length of time. In accordance with this invention, this can beachieved by injecting such a propellant upstream of the nozzle throat,in a subsonic zone, or by means of a counterstreamed injectioncalculated to slow down and at the same time thicken the boundary layerupstream of the injection port, the first propellant dwelling longenough in the thickened part to become hot and vaporized and to then mixand react with a second propellant.

The slowing down of the boundary layer can in certain cases go as far ascreating a stagnant zone, into which can advantageously be injected,directly, a portion of the propellants utilized. When one of thepropellants is injected at high speed and preferably counterstreamed,this results in a separation of the boundary layer upstream of theinjection point and in the formation of a downstream wake. The jet ofpropellant thus creates and bounds two stagnant zones adjacent saidseparation and wake. In accordance with the present invention, recoursemay be had to the upstream or downstream stagnant zone (according as theinjection of a so-called auxiliary propellant is to take place upstreamor downstream of the separation), whereby to confine the two propellantstherein for the time needed for them to heat up, vaporize, mix andreact.

The obtainment of a zone whereat the velocities along the wall are lowenough for expansion of the liquid or liquids to take place, canalternatively be ensured by injecting a multiplicity of small jetsspaced out along the direction of the current, whereby the boundarylayer is progressively thickened and the velocity at which the injectedliquid or liquids are entrained is likewise lowered. These liquids canbe introduced through the medium of rocket nozzle wall elementsembodying at least one network of possibly microscopic orifices obtainedby sintering or perforation and connected to suitable conduits.

The invention likewise relates to a deflecting device comprisingconduits for leading in at least one liquid under pressure, whichconduits being equipped with adjustment valves and have ports over theinner surface of a nozzle wall at points symmetrically arranged aboutthe symmetry axis of said nozzle, and being further provided with meansfor directing the liquid or liquids along said inner surface, forexample in an upstream direction.

In accordance with a specific embodiment, a plurality of reactants, ofwhich one at least remains liquid until it enters the nozzle, areconveyed along corresponding sectors of several circular cross-sectionsof the nozzle, which sectors are spaced from upstream to downstream. Theupstream-directed openings in certain of said sectors make it possibleto very accurately localize the shock wave due to the reaction, whileauxiliary sectors deliver a complement of reactive liquid into thestagnant zones created thus.

The liquids can be conveyed to the joint between two nozzle portions(preferably made of graphite), or to inserts in said nozzle formingstraight spouts which are preferably made of graphite possibly coveredwith an electrolytically deposited metal such as tungsten in particular.

Another embodiment of this invention resides in the injection of amultiplicity of elemental jets through small ducts extending throughcertain elements of the nozzle wall, said elements may be made merely ofporous material.

The description which follows with reference to the accompanyingdrawings, which are filed by way of example only and not of limitation,will give a clear under standing of the various features of thisinvention and of the art of carrying them into practice.

In the drawings filed herewith:

FIGURES 1 and 2 are schematic radial and cross-sectional views,respectively, of a nozzle equipped with a deflector device according tothe invention, utilizing two reactive liquids;

FIGURE 3 is a perspective view in partial section of a composite nozzleequipped with a two-liquid deflector device, and FIGURE 4 is a detailview thereof;

FIGURE 5 is an enlarged radial section taken through one of the spoutsof FIGURE 3;

FIGURE 6 is a highly diagrammatic sectional view of a nozzle wallelement provided with two propellant delivery conduits and of thevarious associated fluid zones;

FIGURE 7 is a similar illustration of a wall element alternativelyprovided with two propellant delivery conduits place near each other;

FIGURE 8 is a schematic perspective view of a nozzle equipped with aperforated panel adapted to deliver two propellants at a multiplicity ofpoints adjacent a wall; and

FIGURE 9 is a highly diagrammatic sectional view of a wall element madeof porous material.

Reference is first had to FIGURES l and 2, which are respectively alongitudinal and a transverse section of a aasassa 83 rocket nozzleillustrated in schematic form, comprising a ferrule 1 and a multisectionlining 2, 3 and 14, made of graphite for instance, whereby to jointlyform the convergent section 4, a threat 5 and a divergent section 6.

The joint between lining sections 2 and 14 is made along a flat orbevelled rim 7c divided into a plurality of sectors which form injectorsindividually supplied through a conduit 8c equipped with a valve 9c,which valve is connected to a steering system (not shown) operatingthrough a control 190. Similarly the joint between lining sections 3 and14 is made along a flat or bevelled rim 7b divided into a plurality ofsectors which forms injectors individually supplied through a conduit 3bequipped with a valve 9b, which valve is connected to a steering system(not shown) operating through a control 10b.

The valves 9 regulate the flow of pressurized liquid conveyed throughconduits 3 to spouts or injectors 7, which spouts may be positioned inthe divergent section 6, the throat 5, or the convergent section 4adjacent the rocket combustion chamber. Said spouts may form an obtuseangle with the upstream part of the wall, in 70 for instance, whereby todirect the liquid flow upstream and thus reduce the distance said liquidis entrained along the wall before reaction.

In the case of certain double-walled nozzles cooled by a thin sheet ofinternally circulating liquid, the deflector device can make use of thecooling liquid, which the circulating system then leads to sector-shapedinjectors equipped with distinct control valves.

Such nozzles are usually employed for liquid-fuel rockets and are cooledby the propellants. However, this invention encompasses this contingencyalso, namely that wherein the liquids used for deflecting the jet arethemselves reactive.

A reactive liquid, be it a monopropellant which dissociates because ofthe temperature of the gas in the primary flow, or a liquid which reactschemically with the unburnt products, offers many advantages over anonreactive liquid.

The reaction of the two propellants or reactive liquids respectivelydelivered by two corresponding injectors 7b, 7c is generally anexothermic one and causes the liquid used to sustain an expansion whichis not only marked (thereby increasing the directional blocking of thenozzle) but also rapid (thus accurately localizing this blocking).

According to this invention, several liquid-s inter-react to create alocalized expansion for blocking the nozzle. Such a disposition, whichis shown in FIGURES l and 2, allows for very accurately locating thepart of the nozzle whercat said expansion takes place and for increasingthe dwelling time of a propellant in the nozzle.

The first sets of injectors 7b supplied through conduit 8b have ports inthe nozzle, for instance somewhat downstream of the throat, and areoriented downstream. The second set of injectors 70, positioned somewhatdownstream of the injectors 7b, are supplied through conduit 80 and haveports in the nozzle with, for example, an upstream orientation. Theseseveral injectors are supplied through chambers 15, 16 embodied in thejoints between the lining blocks 2, 3 and 14.

The first propellant is thus injected into the boundary layer of theprimary flow, thereby thickening and slowing down the same, with anattendant temperature rise in said propellant.

The second propellant is injected with a relatively large momentum, thusassisting in localizing the blocking shockwave 12 between the two setsof ejectors. The gaseous main flow separates from the wall and forms aWake zone 13.

The shock wave 12 and the wake zone "13 have been represented on thefigures. Adjustment is facilitated by the use of liquids. The method ofconstruction of the nozzles according to this invention by no meansimplies unusual difiiculties, the injection chambers '15, 16 and theinjectors 7 being easy to machine within the joints.

The enlarged view of FTGURE 6 provides a clearer picture of the mannerof operation of a device of the type shown in FIGURE 1. FIGURE 6 showstwo sets of conduits 37a and 37b placed side by side and perpendicularlyto the plane of the figure (or alternatively two single ejectors ofnotable development in the same direction), embodied in a nozzle wall31. A first propellant is introduced through the upstream conduit orconduits 37a which may be termed auxiliary conduits) into the boundarylayer 32, which it heats up and partly vaporizes. The second propellantis counterstream injected under relatively larger impulse, through thedownstream conduit or conduits 37b. This second injection produces aslightly upstream separation of the boundary layer, in conjunction witha shock wave 38 which deflects the primary gas flow V, and thisseparation bounds an upstream stagnant zone 35, in which there existcurrents travelling at much lower velocity than the primary jet, andeven back-flowing currents. The propellant injected into the boundarylayer upstream of said stagnant zone mixes with the second propellant inthis zone, in which zone the mixture ignites. It then continues to burnin the progressively accelerated wake 34' until its exit from thenozzle, while preventing entrainment of the primary flow. The upstreamejector 37a must be sufficiently distant from the downstream ejector 37bto ensure suitable heating of the first propellant and substantialthickening of the boundary layer 32, whereby to produce a large mixturearea 33.

FIGURE 7 illustrates an alternative embodiment, which operates in verysimilar fashion to the device of FIGURE 6 and in accordance with whichthe propellant ejectors are juxtaposed.

A first conduit 37c, which may have a considerable transversedevelopment and be prefer-ably turned facing upstream, delivers a firstpropellant into the boundary layer, where its relatively large momentumgenerates a shock wave and then damps out into a wake 34 preceded by adownstream stagnant zone 35. A second conduit 37d, which may be termedan auxiliary conduit, debouches downstream from the first conduitand ata small distance therefrom, in such manner that the small localvelocities and backfiowing currents prevailing in the downstreamstagnant zone 35 enable the second propellant to dwell therein for atleast as long as is necessary for the reaction to be initiated. In otherwords, the purely aerodynamic boundary layer 32, which is disturbed bythe how of the first propellant, is extended by a stagnant zone 35which, from a point 36 onwards, is transformed into an overpressure wake-34 fed by the reaction gas. The flow is separated from said wake by aboundary surface,

FIGURES 3 to 5 relate to an embodiment of the invention wherein thecomposite type nozzle comprises a graphite throat 5a and convergent anddivergent walls 4a and M respectively, made of a laminated plastic-basematerial. A metal ferrule 17 supports the various nozzle sections andforms at 18 a flange whereby it can be joined to the rocket casing. Inthis specific example, a dual inection system is illustrated.

A first set of injection nozzles 7d can be formed, as shown in FIGURE 3,:by pipes 8d sealed directly by a cement into the graphite block 5aconstituting the throat.

A second set of nozzles 7e, disposed in an area lined with a suitableplastic, such as the divergent section 6a, is provided with graphiteinserts r19 (four, say) which are rigidly united with the plastic by acement 20 and are preferably trapezium-shaped in section. The deliveryconduits Se divide into pipes 8,, each of which is sealed into theinsert 19 or retained by means of a flared ter-- minal portion. 'Saidinsert 1 can be protected against: the erosion that chiefly results fromthe reaction, by the: electrolytic deposit or" a metal having a highmelting point, such as tungsten. The liquid is deflected about therounded edge 21 and continues to hug the wall.

FIGURES 8 and 9 illustrate other possible embodiments of the device,which allow for creating, in the boundary layer, a zone wherein thevelocities are sufliciently damped to enable the physical or chemicalexpansion of the injected liquid to take place.

In accordance with the alternative form of construction, shown on FIG.8, the conduits 37 are replaced by a plurality of small holes or bores39, which are disposed in a pattern of several arrays along thedirection of flow. Small pipes branching from a supply pipe 42 arearranged concentrically to small pipes branching from anofher supplypipe 41 and end in the holes 39 respective y.

Lastly, as shown in FIGURE 9, the holes or bores can be microscopic andvery numerous if the wall element 40a which replaces one injector suchas 7b is made of porous material, such as sintered metal, in which casethe chamber 41a could be formed between the liner 43 of nozzle wall 44and said wall 44 itself. In such cases, leaktight seals 45 could beprovided, but the chamber could alternatively be embodied in the wallelement, as shown in FIG. 1.

It is of course to be clearly understood that this invention is by nomeans limited to the specific embodiments described hereinabove by wayof example, but that it also covers all alternative embodiments that canbe obtained by applying such equivalent technical means as result, inparticular, in locally slowing down the boundary layer in a nozzle andin thereby assisting the expansion of at least one liquid.

What is claimed is:

1. A method for deflecting a gas jet discharged at supersonic velocityby a propulsive nozzle having a convergent divergent transverse section,said method comprising the steps of admitting at two successive pointswith respect to the gas jet motion, respectively, a first and secondreactive liquid in metering flow into the gaseous boundary layer huggingsaid nozzle internally, said liquids being adapted to react upon contactwith each other and to expand with formation of a local shock wave whichdeflects said gas jet.

2. A method as claimed in claim 1 wherein at least one reactive liquidis injected in an upstream direction with respect to the gas jet motionto create in the boundary layer a stagnant zone where the reaction takesplace.

3. A method for deflecting a hot jet discharged at supersonic velocityby a solid convergent divergent nozzle, said method comprising the stepsof delivering and second reactive liquid in metered flow into thegaseous boundary layer hugging said nozzle internally, and delivering asecond liquid capable of reacting with said first liquid in saidboundary layer downstream said first liquid, said reactive liquidsreacting with each other locally in the boundary layer and causing alocal shock wave to deflect said gas jet.

4. In combination with a propulsive nozzle of convergent divergenttransverse section discharging a gas jet at supersonic velocity, adeflecting device comprising a first set of injectors regularly spacedalong a cross section of the divergent part of said nozzle, directedinwardly thereof and associated with means forindividually supplyingeither of said first injectors with a pressurized first reactive liquid,a second set of injectors regularly spaced along a cross section of saidnozzle and directed inwardly thereof, the injectors of said second setbeing respectively located in longitudinal correspondence with theinjectors of the first set and associated with means for individuallysupplying either of said second injectors with a second pressurizedliquid capable of reacting with the first liquid injected by thecorresponding first injector, whereby the reaction of said liquidsproduces a localized shock Wave deflecting said gas jet.

5. A deflecting device according to claim 4 wherein the injectors of oneset each consists of a cluster of pipes of small section disposed in asingle row in the vicinity of the nozzle and joined at a distance fromsaid nozzle to a common supply conduit.

6. A deflecting device according to claim 4 wherein an injector forms anarcuate slot in a transverse joint surface between two internal liningsections of said nozzle, said slot being connected to a supply conduit.

7. A deflecting device according to claim 4 wherein the injectors ofsaid second set are oriented upstream with respect to the gas jetmotion, the liquid injected by one of said injectors thereby forming astagnant zone in the boundary layer of the gas jet hugging said nozzleinternally and the reaction of this liquid thereby being localized withprecision.

8. A deflecting device according to claim 7 wherein an injector joinsonto the inner surface of said nozzle through an upstream rounded edgeassisting the adhesion of the liquid injected to said surface.

9. A deflecting device according to claim 4 wherein one set of injectorsis constituted by a plurality of porous elements regularly spaced alonga cross section of said nozzle and each connected to a supply conduit.

10. A deflecting device according to claim 4 wherein H the correspondinginjectors of the two sets respectively delivering said two reactiveliquids are pierced through a common plate which lines said nozzlelocally and form a two directional network of bores.

11. A deflecting device according to claim 10 wherein the boresdelivering the first reactive liquid are supplied through a common firstconduit opening into a distribution chamber embodied in said plate, thesecond reactive liquid being delivered through a network of pipes ofsmaller cross section than said bores and traversing said bores, saidpipes being connected to a common second supply conduit.

References Cited by the Examiner UNITED STATES PATENTS 2,405,785 8/1946Goddard 6035.6 X 2,943,821 7/ 1960 Wetherbee.

2,952,123 9/1960 Rich 60-3554 3,000,178 9/1961 Logerot 6035.54 X3,066,485 12/ 1962 Bertin et al. 60-3554 3,091,924 6/1963 Wilder 6035.543,092,963 6/1963 Lawrence 60-35.54

MARK NEWMAN, Primary Examiner.

SAMUEL LEVINE, Examiner.

T. BLUMENSTOCK, A. L. SMITH,

Assistant Examiners.

1. A METHOD FOR DEFLECTING A GAS JET DISCHARGED AT SUPERSONIC VELOCITYBY A PROPULSIVE NOZZLE HAVING A CONVERGENT DIVERGENT TRANSVERSE SECTION,SAID METHOD COMPRISING THE STEPS OF ADMITTING AT TWO SUCCESSIVE POINTSWITH RESPECT TO THE GAS JET MOTION, RESPECTIVELY, A FIRST AND SECONDREACTIVE LIQUID IN METERING FLOW INTO THE GASEOUS BOUNDARY LAYER HUGGINGSAID NOZZLE INTERNALLY, SAID LIQUIDS BEING ADAPTED TO REACT UPON CONTACTWITH EACH OTHER AND TO EXPAND WITH FORMATION OF A LOCAL SHOCK WAVE WHICHDEFLECTS SAID GAS JET.